Force.com Eclipse plugin installation problem

Installation fails with error 'Md5 hash not as expected'
original error message :

An error occurred while collecting items to be installed session context was:(profile=SDKProfile, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=). Problems downloading artifact: osgi.bundle,com.salesforce.ide.api,23.0.2.201201091635. MD5 hash is not as expected. Expected: 97a6329f82c422a61e9b1bc28be7cace and found ef8b1c2b63c7d04acaa6bf41f4b8570c.

this happens due to corrupted download of jars by eclipse.To fix the problem follow these steps:
1. download all jars manually from
    http://www.adnsandbox.com/tools/ide/install/features/ and
    http://www.adnsandbox.com/tools/ide/install/plugins/
   you can use firefox plugin 'download them all' to download all links in one click.
2. put them in /features/ and /plugins/ directory of eclipse
3.run plugin installation again as you would do normally.It won't download the jars again and it will work without error.

original post:
http://stackoverflow.com/a/9823562/1219463